Condenser apparatus



Patented May 16, 1939 UNITED STATES PATENT OFFICE Westinghouse Electric & Manufacturing Coinpany, East Pittsburgh, 2a., a corporation of Pennsylvania Application November 2'7, 1937, Serial No. 176,875

9 Claims.

My invention relates to heat exchangers and more particularly to the water box of a heat exchanger of the surface-type.

In devices of the above type, particularly surface condensers, undue Wear or erosion of the tubes may occur at their inlet ends on account of turbulence and velocity conditions of the water induced by the velocity at which water enters the box, the direction of entry, and the limited entrance area. Usually, design dictates that the water inlet shall extent through the peripheral wall of the water box, and, of course, the water supply pipe should be no larger than needed to meet pumping requirements economically. The conditions of design thus imposed, are conducive to turbulence and velocity conditions of the water tending to cause tube erosion. Not only may water reach at least some of the tubes at excessive velocity, but the direction thereof may be transverse or tangential rather than in the direction of the length of the tubes, with the result that the water may bring about undue Wear or erosion at the inlet ends of the tubes. It is, therefore, an object of my inventionto provide a water box with deflector or baiile means which gives improved directional effect to the water so that the direction of the latter is changed from that laterally of the box to that generally longitudinally of the tubes.

A further object of my invention is :to provide a condenser water-box having a lateral water inlet with an interior baflie serving to' deflect the direction of flow of water from that generally laterally of the box to that generally longitudinally of the tubes and which baffle defines a'flow path whose-flow area gradually increases towards the inlet ends of the tubes with the result that a gradual decrease in water velocitytakes place so=that the velocity is at a minimum at thetube inlets, the reduction in velocitybeing efi'ectedby conversion of velocity energy into pressure en- 231- A further object of my invention is to providea condenser water box havinga lateral water inlet with an interior circumferential bafile having one end arranged contiguously to the tube sheet and the other end spaced from the water box cover to provide a flow area between the space bounding thebaffle andthe space bounded thereby, the bafile converging outwardly from the tube sheet so that the pathof flow insaid space from the inlet to the tube sheetis a gradually divergent one and the bafile being e'ccentrically displaced in the waterboxtoprovideforcircumferential convergence of the-bounding space in both directions from the water inlet so that more uniform flow conditions :from the outer to the inner spaces may be secured.

These and other objects are effected by my invention as will be apparent from the following description and claims taken in connection with the accompanying drawing forming a part of this application, in which:

Fig. '1 is a longitudinal vertical section through one end of a condenser embodying the present invention;

Fig. 2 is a sectional view taken on the line II--II of-Fig. 1; and,

Fig. 3 is a graphical representation of the velocity trend at points in the water path.

Referring now to the drawing more in detail, numeral I0 indicates, in its entirety, a condenser comprising ashell H having an inlet opening [2 at the top thereof. Within the shell, is a condensing surface 13 comprising a plurality of tubes l4 supported by tube sheets l5 and supporting plates it, one of each appearing on Fig. 1. At one end of the shell II, is a water box structure I-8 having a sidednlet l9 and an air vent 2| connecting the top of-the inlet water box with the outlet water b'ox. Within the water box H3, is a deflector or baffle 2-0, which modifies the direction of how and the velocity of entering water.

The shell H, as herein shown, is made from steel plate welded together, and is curved in cross-section as best shown in Fig. 2. The shell is provided, at the bottom, with a hot well 24 of conventional construction.

The-tubes Mextend longitudinallyof the shell and are supported by end tube sheets l5 and intar-mediate support sheets l6, carried, in turn, bytheflanges '26 andsupports' 22, respectively.

The inlet water box I8 is held in place with respect to thetube sheet l5zand end of the shell by the flange :28 and it-is provided with a cover 29 having the usual hand holes 3|] and hand hole cove-rs:30a.- The water boxhas an inlet [9 opening through aside thereof and through which water or other fluid may enter for circulation through the tubes I4. While only one water box .appearsonfragmentary Fig. 1, it is to be understood'thatthe condenser is provided with a water box at each end, as is customary.

LWithin the inlet-.water box,.is disposed a baille 2|], which defines, with the box, a baiile-bounding water passage or space 3| in communication with the inlet. Thebaiilehasone end arranged contiguouslyto-the tube .sheet lli and has its other endspacediromthecoverZS to provide the how area -,3la,,;afiord-ing communication of the outer bathe-bounding space 3| with the interior bafllebounded space 32.

The baffle preferably converges toward the cover 29 so that the space 3| diverges toward the cover and the space 32 diverges toward the tube sheet with the result that the flow path including these spaces gradually diverges in the direction of flow, the area 3la being of suitable size, in order that the velocity may be reduced to a minimum just before it enters the tubes.

Preferably, the baffle is located eccentrically of the tube sheet I5 and of the water box l8, being offset away from the inlet opening I9, to provide for said outer water path or passage 3| converging away from the inlet in both directions so that a more uniform velocity and pressure condition may be maintained in such path or annular passage, with uniform supply of water therefrom through the flow area 3|a to the space 32 and the tubes l4.

As clearly indicated by the arrows in Figs. 1 and 2, the water passing through the inlet water box enters the latter at opening I9, flows circumferentially along the outside of baffle 20, then over the end of the bafile and through the flow area 3 la to the interior 32 and thence to the tubes M. Not only is the direction of the flow of water changed from laterally of the tubes to longitudinally thereof before the tubes are reached, but the velocity is reduced because of the increasing flow areas along the path from the water box inlet to the tube entrance. This results in a material reduction in both the velocity and the turbulence of the water as well as in better distribution to the tubes. Furthermore, distribution is improved by the great uniformity of flow through the area 3m provided by eccentric displacement of the baffle. Therefore, not only is the energy of the entering water used to best advantage to secure circulation without undue tube wear, but more uniform flow through all of the tubes is conducive to improved condenser performance.

The changes in velocity at various points in the water path are indicated graphically in Fig. 3,

ie velocity dropping from the point B at the entrance to the water box until a point (F) is reached just before entrance to the tubes. The velocity thereafter rises from point F to point H, within the tubes, after which it is substantially constant.

In order to prevent turbulence resulting from flow of water over the end of the baflle at a point immediately adjacent the inlet and to provide for more uniform supply of water to all of the tubes, an additional baffle 34, which preferably, is a continuation of baffle 20, is arranged over the inlet l9.

While I have shown the baffle 20 as attached to the tube sheet, it may be supported by the cover plate, if desired.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

What I claim is:

1. In a heat exchange device, a tube sheet, an inlet water box associated therewith, and annular deflecting means within the water box for changing the direction of flow of the water from that laterally of the water box to that longitudinally of the tubes.

2. In a heat exchange device, a tube sheet, an inlet water box associated therewith, and annular deflecting means within the water box for changing the direction of flow of the water from that laterally of the water box to that longitudinally of the tubes and said deflector being constructed and arranged so that the path of water flow in the box diverges in the direction of flow.

3. In a heat exchange device, a tube sheet, a water box structure associated therewith having a lateral inlet, and annular deflecting means within the water box for directing flow of the cooling water away from the tube sheet and then toward it.

4. In a heat exchange device, a tube sheet, a water box structure associated therewith and having a lateral inlet opening for water, and means within the water box for changing the direction of flow of the water from that laterally of the water box to that longitudinally of the tubes, said means comprising a shell which is approximately the frustum of a right circular cone having one end arranged contiguously to the tube sheet and whose other end is spaced from the water box cover to provide a flow path from the region within the water box located exteriorly of the shell to the region located interiorly of the shell.

5. In a heat exchange device, a tube sheet, a water box structure associated therewith and having a lateral inlet opening for water, and means within the water box for changing the direction of fiow of the water from that laterally of the water box to that longitudinally of the tubes, said means comprising a deflector which defines, with the peripheral wall of the box, a bounding circumferential space with which the inlet communicates and which bounds a space communicating with the tubes, one end of said deflector being arranged contiguously to the tube sheet and the other end being spaced from the water box cover to provide a flow area from said first space to said second space, said first space diverging away from the tube sheet and the second spacing diverging toward the tube sheet and said flow area being such that the flow area gradually increases along the path of flow.

6. In a heat exchange device, a tube sheet, a water box having peripheral wall and cover portions and having a water inlet extending through the wall, and means within the water box for changing the direction of flow of water from that laterally of the water box to that longitudinally of the tubes, said means comprising a deflector constituting the frustum of a right circular conical shell, the base thereof abutting the tube sheet and the top thereof being spaced from the water box cover.

'7. In a heat exchange device, a tube sheet, a water box having a peripheral wall and a cover and provided with an inlet opening for water extending through the peripheral wall, and 6 means within the water box for changing the direction of flow of water from that laterally of the water box to that longitudinally of the tubes, said means comprising a circumferential shell having one end arranged contiguously to the tube sheet and having its other end spaced from the water box cover to provide a flow area and said shell converging from the tube sheet toward the cover to provide a bounding space which diverges away from the tube sheet and a bounded space which diverges toward the tube sheet.

8. In a heat exchange device, a tube sheet, a water box associated therewith and having a pcripheral wall and cover and provided with an inlet opening for water extending through the peripheral wall, and means within the water box for changing the direction of flow of the water from that laterally of the water box to that longitudinally of the tubes, said means comprising a circumferential shell having one end arranged contiguously to the tube sheet and having its other end spaced from the cover sufficiently to provide a flow path from the region within the water box located exteriorly of the shell to the region located interiorly of the shell, said shell converging outwardly from the tube sheet toward the cover so that the water flow path from the inlet to the tubes and including the spaces bounding the shell and bounded by the latter is gradually divergent in the direction of flow and said shell being eccentrically displaced in the water box so that the circumferential space bounding it gradually converges from the water inlet in both directions.

9. In a heat exchange device, a tube sheet, a water box having a peripheral wall and cover associated therewith and provided with an inlet opening for water extending through the peripheral wall, and means within the water box for changing the direction of flow from that laterally of the water box to that longitudinally of the tubes, said means comprising first and second deflectors, the first deflector including a circumferential shell having one end arranged contiguously to the tube sheet and having its other end spaced from the water box cover to provide a flow area and the second deflector being arranged to interrupt said flow area at the immediately adjacent region of the water inlet.

ULRICH A. TADDIKEN. 

